Tiawia



Sept. 15, .1925. 1,554,075

E. EGEN/ESET- AL ELECTRIC FURNACE Filed Aug. 2. 1923 fatented Sept. 15,1925.

UNITED STATES PATENT OFFICE.

ERLING EG-ENZES, OF CHRISTIANIA, AND OLE SANDVOLD, OF NOTODDEN, NORWAY,

ASSIGNORS TO NORSK HYDRO-ELEKTRISK KVAELSTOFAKTIESELSKAB, 0F CHRIS-TIANIA, NORWAY.

ELECTRIC FURNACE.

Application filed August 2, 1923.

To all whom it may concern:

Be it known that we, ERLING Eennfns and Slurry-torn, bot-h subjects ofthe King of Norway, residing at Huitfeldts Gate 36, Christiania, and atNotodden, respectively, both places in the Kingdom of Norway, haveinvented certain new and useful Improvements in Electric Furnaces; andwe do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to wiieh it appertains to make and use the same, reference being hadto the accompanying drawings, and to letters or figures of referencemarked thereon, which form a part of this specification.

The present invention relates to electric furnaces wit-h long stablelight arcs, and a method of operating the same whereby gas reactions areeffected, the best possible utilization being made of the heat of thegases.

'Ihese furnaces usually operate in such a manner that the gases from thefurnaces pass through a boiler and then through the rest of theapparatus which, in the present case, it is unnecessary to describe.

@ne electrode of the furnace (the furnace cooler) is cooled with largequantities of water. The greater part of the water runs away, while onlya small quantity is used for feeding the boiler.

According to the present invention, the ieat of the gases can be betterutilized by allowing the feed water of the boiler to pass under pressurefirst of all through the furnace cooler, whereupon it is forced througha feed valve into the boiler. Another advantage is, that without anyrisk of a leakage occuring in the boiler, the feed valve can preventwater and steam from forcing its way into the furnace.

In order to prevent the water in the cooler from penetrating into thefurnace either 011 account of leakage or from a crack in the boiler, thewater is allowed to pass through the furnace cooler at somewhat lowerpressure than the gas iressure in the furnace. In the event of aleakage, a little of the gas would make its way into the cooling water.It would, however, by means of specially constructed cont-rollingapparatus, be easy to observe when the gas starts to penetrate into thecooler and the furnace could then Serial No. 655,326.

be stopped. In the case of normal opera tion, the water 1s thenconducted from the furnace cooler into a steam injector or some otherkind of feeding apparatus, which forces the water into the boiler wherethe steam pressure is kept somewhat higher than the gas pressure.Besides, reducing pressure in the cooler, the fire box and the firetubes, it prevents the nitrous gases in the event of leakage, fromforcing their way into the boiler.

A form of apparatus for carrying out our method is diagrammaticallyillustrated in the accompanying drawing, wherein 11 deslgnates a furnacetube having apertures 9, through which air, preferably preheated,enters. 1O designates the isolated electrode, whereas the fire tubes 8and the cooler 1 form the other electrode which may preferably begrounded.

Through a tube 6 in the cooler 1, the furnace gases pass into the firebox 7, and from there to the fire tubes 8. The fire box 7 and tubes 8are placed in the boiler 2. The cooling water is fed to the cooler by acon duit 12 and passes from the cooler, after becoming heated, into aconduit 18 and is forced by a steam injector 5 through a feeding valve 3into the boiler 2. If gas enters the feed water this can immediately beobserved in a glass l.

lVe claim 1. In the operation of electric furnaces using long stablearcs and discharging into a steam boiler, the method which comprisessupplying cooling water to one of the electrodes and thereafterintroducing said water, preheated by the heat abstracted from saidelectrode, into the boiler.

2. In the operation of electric furnaces using long stable arcs anddischarging their gaseous products into a steam boiler, the method whichcomprises cooling the upper electrode by water at a pressure less thanthe pressure of the furnace gases, feeding such water, preheated by theheat abstracted from said electrode, into the boiler and separatingfurnace gases leaking into the cooling water.

3. In the operation of electric furnaces using long stable arcs anddischarging their gaseous products into a steam boiler, the method whichcomprises cooling the upper electrode by water at a pressure less thanthe pressure of the furnace gases, feeding such Water, preheated by theheat abstracted from said electrode, into the boiler separating furnacegases leaking into the cooling water, and maintaining the steam pressurein the boiler higher than the pressure of gases in said furnace.

4c. In a plant comprising an electric long are furnace, a boiler forcooling the furnace gases including an electrode cooler, thecoinbination of means to feed Water to said cooler under less pressurethan the pressure of gases in the furnace, and means to supply thecooler with Water preheated by said cooler.

In testimony that We claim the foregoing as our invention We have signedour names.

ERLING EGENZES. OLE SANDVOLD.

